Fan nozzle

ABSTRACT

A fan nozzle for cleaning a surface with an abrasive blast media is constructed of a longitudinal body having an axial pathway through which the media is passed under pressure for release from a substantially rectangular cross-sectional outlet to release the media in a substantially flat, wide path. A first transition zone provides a conversion in the axial pathway from the inlet cross-section to the substantially rectangular cross-section of the outlet opening. A second transition or convergence zone first reduces and then expands the cross-section of the axial pathway for providing a Venturii acceleration of the media as it passes through the nozzle. The transition zone and the convergence zone may be coexistent along a portion of the axial pathway.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject invention relates generally to nozzles for releasingabrasive media under pressure and is specifically directed to a fannozzle for releasing the abrasive media in a wide, flat path.

2. Discussion of the Prior Art

Fan nozzles are relatively well known in the industry and are used torelease an abrasive media under pressure in a substantially wide, flatpath instead of in a circular pattern as with nozzles with roundopenings. Such nozzles are particularly convenient when the abrasivemedia is being used to clean a large surface and it is desirable to passthe nozzle over the surface in sweeping motions.

Typically, such nozzles are adapted to be connected to a common sourceof pressurized abrasive media, which normally is a coupler on the end ofa hose of circular cross-section. The circular cross-section of theinlet end of the nozzle is then in communication with a convergence zonewherein the cross-section of the nozzle is less than the cross-sectionof the inlet of the nozzle or the outlet of the pressure source. Whenthe media passes through the convergence zone, the velocity of theflowing media accelerates as the media is introduced into the largercross-section of the rectangular outlet of the nozzle, caused by theVenturii effect of passing the media through the reducing and thenexpanding zones.

Such nozzles have been around for many years. Some typical examples areshown and described in U.S. Pat. Nos. Re. 34,584; 5,704,825 and6,626,738. Each of these patents use a Venturii-type convergence zonefor reducing and then expanding the cross-sectional area of the nozzleto cause acceleration of the media as it is expelled through the nozzleoutlet.

While such nozzles may be useful for the intended purpose of providing apressurized blast media in a flat path for cleaning surfaces, they allhave a common drawback. Specifically, the prior art nozzles provide foran immediate transition from a generally circular inlet cross-section toa generally rectangular outlet cross-section. This creates wear pointsat the transition, as well as turbulence. In addition, such aconfiguration creates hotspots in the media flow as the media isreleased from the nozzle.

With specific reference to U.S. Pat. No. Re. 34,854, it will be notedthat the convergence section has an inlet end that is of a rectangularcross-section, such inlet end being adapted to connect directly to thecoupler of circular-cross section. This provides for an immediatetransition from a circular source to a rectangular nozzle pathway,creating a wear point at the transition, as well as generatingturbulence in the flow. The Venturii convergence zone is all ofrectangular cross-section.

The blast nozzle of U.S. Pat. No. 5,704,825 also shows an immediatetransition from a circular inlet to a rectangular convergence zone andhas the same drawbacks as the nozzle of U.S. Pat. No. Re 34,854.

The fan nozzle shown in U.S. Pat. No. 6,626,738 shows a circularcross-section Venturii in communication with the inlet end of thenozzle. Specifically, the inlet is circular and transitions into anellipse prior to an expanding rectangular fan nozzle outlet. While animprovement over earlier designs, this still does not overcome the hotspots typically present in a fan nozzle.

SUMMARY OF THE INVENTION

The subject invention is a fan nozzle for cleaning a surface with anabrasive blast media. The nozzle is constructed of a longitudinal bodyhaving an axial pathway through which the media is passed under pressurefor release from a substantially rectangular cross-sectional outlet torelease the media in a substantially flat, wide path. Within the body ofthe nozzle and along its axial pathway there is a transition zoneproviding a conversion in the axial pathway from the inlet circularcross-section to the substantially rectangular cross-section of theoutlet opening.

There is also a second transition zone or convergence zone within thebody of the nozzle and along the axial pathway intermediately of theinlet end and the outlet end for first reducing and then expanding thecross-section of the axial pathway within the longitudinal body forproviding a Venturii acceleration of the media as it passes through thenozzle. In the preferred embodiment of the invention, the transitionzone and the convergence zone are coexistent along a portion of theaxial pathway.

The convergence zone may reduce the cross-sectional area of the axialpathway in a plane parallel to the release path. Alternatively, theconvergence zone may reduce the cross-sectional area in a planeperpendicular to the release path. In addition, where desired, theconvergence zone may reduce the cross-sectional area of the axialpathway in planes both parallel to the release path and perpendicular tothe release path.

In the preferred embodiment of the invention, the nozzle comprising thelongitudinal body, including the inlet end, the outlet end and thetransition zone and the convergence zone may be of unitary construction.

By providing the transition zone in accordance with the subjectinvention the media flow is converted from a flow of circularcross-section to a flow of rectangular cross-section over a longitudinalpath. This provides a smooth transition and minimizes both turbulenceand wear. In addition, by providing a smooth transition, the abrasiveparticles are more evenly distributed throughout the flow areacross-section whereby the hot spots in the media flow outlet aresubstantially reduced.

The transition zone is used in combination with a convergence zone toboth convert the cross-sectional pattern of the flow and accelerate theflow to provide improved fan nozzle performance with a desirable wide,flat path with a minimum of hot spots. This permits more even flow ofthe media and more even cleaning or preparation of the surface beingtreated.

In the preferred embodiment of the invention, the convergence zone andthe transition zone are coexistent along the longitudinal media flowpath. However, it is not necessary that the zones be coexistent.

Also, the subject invention incorporates a convergence zone which canintersect the flow path is a plane parallel to the fan nozzle outlet, ora plane perpendicular to the fan nozzle outlet, or both parallel andperpendicular, depending on preference.

The fan nozzle of the subject invention produces a desirable wide, flatmedia flow with a minimum of hotspots, making it useful for a largevariety of applications. The features of the invention will be made moreapparent by reference to the accompanying drawings and detaileddescription.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the fan nozzle of the subject invention.

FIG. 2 is a diagrammatic view of the axial pathway of the nozzle,diagrammatically illustrating the relationships of the cross-sectionalareas of the interior of the nozzle throughout its length.

FIG. 3 is a slice view of the nozzle looking from the inlet toward theoutlet.

FIG. 4 is a slice view of the nozzle, looking down on the nozzle in aplane perpendicular to the plane of the fan expansion section.

FIG. 5 is a sectional view taken along line 5-5 of the slice view ofFIG. 3.

FIG. 6 is a cross-sectional view of the nozzle taken along line 6-6 ofFIG. 1

FIG. 7 is a top view of the nozzle showing in phantom the axialpassageway.

FIG. 8 is a top view of an alternative embodiment of the nozzle, showingin phantom a modified axial passageway.

FIG. 9 is a diagram showing the flow through a nozzle in accordance withthe subject invention.

FIG. 10 is a diagram contrasting the flow through a prior art nozzleconfiguration.

DETAILED DESCRIPTION

With specific reference to FIG. 1, the fan nozzle of the subjectinvention comprises a longitudinal body 20. The fan nozzle is dividedinto three main sections, the inlet section 22, the transition section24 and the expansion section 26. A cross-sectional view of the nozzle,taken along line 6-6 of FIG. 1 is shown in FIG. 6. The inlet 28 of thenozzle is adapted to be coupled to a source of pressurized media and istypically of a generally circular cross-section, but may be modified, asat 30 to receive a connector on the source (not shown). Inwardly of theinlet 28, the inlet section 22 is of a rectangular cross-section, asshown in FIGS. 2-5 for distributing the pressurized air or other fluidand the abrasive throughout the fall cross-sectional area of the nozzle.Specifically, the inlet end 28 of the nozzle provides a transition fromthe circular connector at 28 a to a rectangular cross-section at 31 withthe remainder 33 of the inlet section being of rectangularcross-section. An axial pathway 34 extends the entire length of thenozzle assembly and connects the outlet 32 with the inlet 28.

The convergence transition section 24 of the nozzle flows from the inletsection 22 into a throat 25 which is the inlet to the expansion section26. The convergence transition section provides a reduction in area ofthe rectangular cross-sectional flow path in the inlet section. Thisprovides a Venturii effect for accelerating the fluid/abrasive mix. Thethroat determines airflow consumption. As shown in FIGS. 2-5, the entireconvergence transition section is of continuously reducing, rectangularcross-section. The expansion section 26, also of rectangularcross-section, then “fans out” or expands in one plane and terminates ina rectangular, flat outlet 32. This provides full divergence of thefluid/media mix across the entire cross-sectional area of the outlet 32for dispersing the mix onto a target object.

As better shown in FIG. 2, the inlet 28 is of a cross-section adapted tofit the source of the fluid/media flow, as shown at 28 a. This is thenconverted to a generally rectangular cross-sectional area as shown at 22a, which extends the entire length of the inlet section 22, as indicatedat 22 a and 22 b. The cross-sectional area is continuously reduced inthe convergence transition section 24, as indicated at 24 a, 24 b and 25a, with the final cross-section 25 a defining the nozzle throat forcontrolling flow. Specifically, the cross-sectional areas 22 a and 22 bare substantially the same for the entire length of the inlet section22. Cross-sectional areas 24 a, 24 b and through to 25 a arecontinuously reducing. Cross-sectional areas 26 a, 26 b, through 26 c inthe nozzle expansion zone are continuously increasing. The diagrammaticcross-sections above the fan nozzle illustration show thecross-sectional area configuration including circular inlet 28 a, thetransition to rectangular cross-section at 22 a, the transition section24, the throat 25 and the expansion section 26 terminating at the outlet32. The sectional area 25 a defines the controlling throat 25. Thecross-sectional area is then expanded in the expansion section 26, asindicated at 26 a, 26 b and 26 c.

A longitudinal slice through the nozzle 20 and looking from the inletopening 28 toward the outlet opening 32 is shown in FIG. 3. This clearlyshows the relationship between the various junctions of the nozzle, withthe circular-to-rectangular transition present at 28 a, the rectangularcross-sectional inlet section 22, the converging transition section 24and throat 25 terminating in the expansion section 26. Thisconfiguration permits a continuous, smooth flow of the media through thenozzle without any abrupt transition points, reducing turbulence andminimizing wear. It also permits the media flow to reshape itselfwithout creating hotspots due to interruption in flow or increasedresistance to flow in specific areas. Another slice view, looking downon the nozzle, is shown in FIG. 4.

FIG. 5 is an end view of the nozzle, taken at line 5-5 of FIG. 3 andlooking in the direction from the inlet 28 toward the outlet 32. Thisshows the relationship between the inlet 28, the transition 22 a, theinlet section 22, the convergence transition section 24, the throat 25,the expansion section 26 and the outlet 32.

As better shown in FIGS. 6 and 7, the convergence transition section 24begins with the full cross-sectional area 50 at the junction between theinlet section 22 and the convergence section 24. The cross-sectionalarea is continually reduced by the tapered wall 52 of the body, asindicated in FIGS. 1, 6 and 7, terminating at the throat 25. Thenbeginning at the throat outlet 54 the cross-section continuallyincreases in a plane substantially perpendicular to the converging planeof the transitions section, as indicated by the outward fanning ortapered wall 56 of the nozzle. This creates a Venturii effectacceleration of the media as it flows through the nozzle and is expelledthrough outlet 32.

The transition section of the embodiment of FIGS. 1, 6 and 7 is in asingle plane running parallel to the opening 32 in nozzle 26. Analternative embodiment is shown in FIG. 8. In this configuration, theconvergence section 48 is perpendicular to the plane of the nozzle 26.However, in function it operates in the same manner as the configurationof FIGS. 1 and 6. Namely, the cross-section of the convergence sectionis the same as the inlet section at junction 60, and reduced by thetapered wall 62 to the junction 64 between the convergence section 58and the nozzle 26. The cross-section then expands in the tapered fannozzle section 26, again creating a Venturii effect acceleration ofmedia toward the nozzle outlet 32.

The two configurations of the convergence section may be usedindependently of one another, or in combination. Also, while theconvergence section(s) and the transition section 24 are shown aslongitudinally separated in the illustrated embodiments, it should bereadily understood by those who are skilled in the arts that these twosections could be coexistent along the flow path of the nozzle. Byplacing them in a coexistent position, the nozzle can be of a morecompact design.

The flow path of a nozzle in accordance with the present invention isgraphically shown in FIG. 9. As can be seen, once the media flow entersthe nozzle 26 at the transition/nozzle junction 44, all of flow has beensmoothly converted into a rectangular cross-section and is confined inthe shaded area 70. Then, because of the Venturii effect of theconvergence zone, the flow only has to expand and accelerate outwardlyas indicated by arrows 72 and 74.

This is to be contrasted with the prior art designs, as graphicallyillustrated in FIG. 10. In these configurations, there is an abruptchange in shape at the junction between the inlet section 100 and therectangular nozzle section 102. This is true even when a Venturiiaccelerator is used and the cross-section is reduced, as indicated at104. This results in some of the flow being trapped at the end of theconvergence section when the convergence section is of circularcross-section, as indicated at 106 and 108. The media flow then musttravel in a direction perpendicular to the flow outwardly into thenozzle, as indicated at 110 and 112. This results in turbulence, a wearpoint in the nozzle, and hotspots in the flow as more of the mediavolume is in the areas of the arrows 110 and 112 and less of the mediavolume is in the area of the outer arrows 114 and 116.

The transition section of the nozzle of the subject invention minimizesturbulence, reduces wear and provides for a more even flow. When used incombination with a convergence section, the fan nozzle of the subjectinvention provides a smooth, wide, flat flow of media with a minimum ofhot spots. While certain features and embodiments of the invention havebeen described in detail herein, it should be understood that theinvention includes all modifications and enhancements within the scopeand spirit of the following claims.

1. A nozzle for cleaning a surface with an abrasive blast media, thenozzle comprising: a. a longitudinal body having an axial pathwaytherethrough, an inlet end adapted to be connected to a source whereinthe abrasive media is introduced into the nozzle under pressure, theinlet end of a cross-section compatible with the cross-section of thesource at the point where the media is introduced into the nozzle; b. anoutlet end having an opening of a flat, substantially rectangularcross-section for releasing the abrasive media in a wide, substantiallyflat path; c. a first transition zone between the inlet end and theoutlet end, the transition zone providing a conversion in the axialpathway from the inlet cross-section to the substantially rectangularcross-section of the outlet opening along a portion of the longitudinalbody; and d. a second transition zone for reducing the cross-sectionalarea of the axial pathway body intermediately of the inlet end and theoutlet end.
 2. The nozzle of claim 1, The nozzle of claim 1, wherein thefirst transition zone and the second transition zone are coexistentalong the axial pathway within the longitudinal body.
 3. The nozzle ofclaim 1, wherein the cross-section of the inlet end is substantiallycircular.
 4. The nozzle of claim 3, wherein the first transition zoneextends along a portion of the axial pathway within the longitudinalbody intermediately of the inlet end and the outlet end and provides aconversion from a substantially circular cross-section at the inlet endto a substantially rectangular cross-section at the outlet end.
 5. Thenozzle of claim 4, wherein the second transition zone extends along aportion of the axial pathway within the longitudinal body and firstreduces the cross-section of the axial pathway within the longitudinalbody.
 6. The nozzle of claim 1, further including an expansion zonebetween the second transition zone and the outlet for diverging anddischarging the media.
 7. The nozzle of claim 5, further including anexpansion zone between the second transition zone and the outlet fordiverging and discharging the media.
 8. The nozzle of claim 5, whereinthe first transition zone and the second transition zone are coexistentalong a portion of the axial pathway within the longitudinal body of thenozzle.
 9. The nozzle of claim 7, wherein the cross-section of the inletend is substantially circular.
 10. The nozzle of claim 8, wherein thefirst transition zone extends along a portion of the pathway within thelongitudinal body intermediately of the inlet end and the outlet end andprovides a conversion from a substantially circular cross-section at theinlet end to a substantially rectangular cross-section at the outletend.
 11. The nozzle of claim 1, wherein the longitudinal body, includingthe inlet end, the outlet end and the first transition zone and thesecond zone are of unitary construction.
 12. The nozzle of claim 1,wherein the second transition zone reduces the cross-sectional area ofthe axial pathway within the longitudinal body in a plane parallel tothe release path.
 13. The nozzle of claim 1, wherein the secondtransition zone reduces the cross-sectional area of the axial pathwaywithin the longitudinal body in a plane perpendicular to the releasepath.
 14. The nozzle of claim 1, wherein the second transition zonereduces the cross-sectional area of the axial pathway within thelongitudinal body in a plane parallel to the release path and in a planeperpendicular to the release path.
 15. A nozzle for cleaning a surfacewith an abrasive blast media, the nozzle comprising: a. a longitudinalbody having an axial pathway therethrough, an inlet end of substantiallycircular cross-section and adapted to be connected to a source also ofsubstantially circular cross-section wherein the abrasive media isintroduced into the nozzle under pressure, the inlet end compatible withthe source at the point where the media is introduced into the nozzle;b. an outlet end having an opening of a flat, substantially rectangularcross-section for releasing the abrasive media in a wide, substantiallyflat path; c. a first zone between the inlet end and the outlet end, thetransition zone providing a conversion in the axial pathway from thesubstantially circular inlet cross-section to the substantiallyrectangular cross-section of the outlet opening along a portion of thelongitudinal body; d. a second transition zone for reducing thecross-sectional area of the axial pathway body intermediately of theinlet end and the outlet end; e. and an expansion zone for dispersingthe media.
 16. The nozzle of claim 15, wherein the first transition zoneand the second transition zone are coexistent along the axial pathwaywithin the longitudinal body.
 17. The nozzle of claim 15, wherein thesecond transition zone extends along a portion of the pathway within thelongitudinal body and first reduces the cross-section of the nozzle andthen expands the cross-section of the nozzle to provide a Venturiiacceleration of the media as it passes through the nozzle.
 18. A nozzlefor cleaning a surface with an abrasive blast media, the nozzlecomprising: a. a longitudinal body having an axial pathway therethrough,an inlet end adapted to be connected to a source wherein the abrasivemedia is introduced into the nozzle under pressure, the inlet end of across-section compatible with the cross-section of the source at thepoint where the media is introduced into the nozzle; b. an outlet endhaving an opening of a flat, substantially rectangular cross-section forreleasing the abrasive media in a wide, substantially flat path; c. afirst transition zone between the inlet end and the outlet end, thetransition zone providing a conversion in the axial pathway from theinlet cross-section to the substantially rectangular cross-section ofthe outlet opening along a portion of the longitudinal body; and d. asecond transition zone defining a convergence zone for reducing thecross-sectional area of the axial pathway body intermediately of theinlet end and the outlet end, the convergence zone extending along aportion of the pathway within the longitudinal body and for firstreducing the cross-section of the axial pathway within the longitudinalbody and then expands the cross-section of the axial pathway within thelongitudinal body to provide a Venturii acceleration of the media as itpasses through the nozzle, wherein the transition zone and theconvergence zone are coexistent along the axial pathway within thelongitudinal body.
 19. The nozzle of claim 18, wherein the transitionzone and the convergence zone are coexistent along the axial pathwaywithin the longitudinal body.
 20. The nozzle of claim 19, wherein theconvergence zone reduces the cross-sectional area of the axial pathwaywithin the longitudinal body in a plane parallel to the release path.21. The nozzle of claim 19, wherein the convergence zone reduces thecross-sectional area of the axial pathway within the longitudinal bodyin a plane perpendicular to the release path.
 22. The nozzle of claim19, wherein the convergence zone reduces the cross-sectional area of theaxial pathway within the longitudinal body in a plane parallel to therelease path and in a plane perpendicular to the release path.